Paris is a romantic city. The architecture, the lights, the food, the language; it’s hard to deny that this city is a place for love.

One of the classic expressions of romance in the City of Light is the collection of love padlocks on some of Paris’ most classic bridges. Love locks are a simple thing: a couple writes their names on a padlock, locks it to one of the bridges, and if they are really committing to everlasting love, throws the key into the Seine.

The weight of love in Paris is so big that a few years ago, town hall was concerned about the influence of the locks on the city’s architectural integrity, and one night, all of the thousands of locks were cut down – although the culprit remains unknown. But even French bureaucracy can’t win in the battle of love, and locks returned, in all colors and sizes.

You’ll find the biggest assortment on Pont des Arts and Pont de l’Archevêché (which bridge you choose depends on which type of love you are trying to express), where Flickr user jrodmanjir snapped this photo.

Today’s Photo of the Day was taken on Paris‘ Pont des Arts bridge, where it is tradition to write your name and your lover’s on a padlock and attach it to the railing to symbolize your unbreakable bond. It’s a tradition popular all over the world, from Florence to Taiwan (check out Gadling’s gallery from Cologne, Germany. Over the years, many cities have tried to remove the locks or limit new additions, but true love prevails and it remains a fun way to leave a symbol of your beloved. Thanks to Flickr’s Luke Robinson for the photo, we hope some of that lovey doveyness followed you home from France!

Love locks are a romantic symbol of true love: Walk across a bridge with your sweetheart, affix a lock scrawled with your names to the structure, and then toss the key into the river below.

The tradition is said to have originated on the Ponte Milivio in Italy, but from Australia to Uruguay the practice has caught on. I found these on the Hohenzollern Bridge in Cologne, an overpass that is becoming so packed with padlocks the bridge’s operator has threatened to saw them off. After public outcry over the matter, the company was forced to have – you guessed it – a change of heart.

From near and far, the love locks add a little glitter to a bridge that is otherwise gritty and dull. But up close its not always picture perfect: there were a few spots where fence wires were cut, perhaps in an effort to release scorned lovers of their shackles. Two little boys crossed the bridge tugging on the padlocks as they went along, trying to shake them loose (ladies, watch out – the heartbreaking starts early!). Below the bridge, I was actually surprised there weren’t vendors hawking padlocks to tourists for 20 euros a pop. I guess there are some things that are still sacred.

Click through the gallery to see more padlocks on the Hohenzollern Bridge in Cologne, and let me know where else you’ve found them below!